General Model Output Discussion

[Michael Fishermans Friend]

That HP just collapses though, after 144 I thought it would link up with the Scandi HP but over the UK, I'm sure advisers like GP will advise us whats forecasted to be happening off the eastern seaboard by next week, certainly unexpected though with a continued -AO forecast for the foreseeable future. Anybody know what the GEM 12z was like as it has been in tandom with the ECM?

[tinybill]

i know its a long way off but if this happens i wont mind !! happy new year all

[Thundery wintry showers]

It isn't supported by the teleconnections which favour some kind of mid latitude block over or to the north of Britain, and the breakdown happens at T+192, so I don't think it's worth reading too much into the ECM's extended output- the same goes for the colder, wintrier picture that the GFS shows. Winds should be vectored somewhere between N and E until T+168 bringing snow showers, that's the main thing that the models are showing. The ECMWF is overall the most accurate model in the world, but no model is accurate beyond 6 days out.

And indeed, if the south-westerlies do return by T+216 (which I find unlikely) it will nonetheless have been the longest cold spell since the 1980s.

[NorthantsSnow]

Although the ECM past T144 is a concern, I really don't think it's something to lose sleep over at the moment. The models are all having their ups and downs, mainly I think because of the blocking. Though an overdone phrase they are struggling.

Disagree. Collectively the models, certaintly in the short to medium term, are the most consistent they have been for a very long time IMO. Normally they are more erratic than this during winter.

Doesn't mean they are right of course and the detail in terms of precip for example will never be clear until within T48 or even T24.

[Cecil Hogmanay Melchett]

GEM is ever so slightly better than ecm at 120h.

The unfortunate trend this evening however is an unexpected powering up of the Northern arm.

Not sure many of us saw this coming and highlights perfetly the uncertainty of looking past 120h.

[SMU]

http://www.wetterzentrale.de/pics/Rjma1921.gif

JMA 192-- NOTHING like the ECM & look at the juicy WEHEEHEAAA up the western part of Greenland-

So either every model is wrong tonight or its a wobbler from the ECM- didnt this happen the other day with the gfs....

S

Edited December 31, 2009 by Steve Murr

[weather eater]

Its funny how we get the same old reactions to model runs, its either over the top optimism or over the top pessimism. Past about 144hrs sometimes less, runs diverge and evolve differently, every model, every run, every day, all seasons. Anyone of the recent outputs could be the correct evolution or none of them. The only thing the ECM proves is that its possible that January may not turn out to be a record breaking cold month to rival those of the past, and that hyperbole predictions have no place in model discussions. One thing for certain many other evolutions will be on display over the next few days.

Edited December 31, 2009 by weather eater

[Frosty.]

It isn't supported by the teleconnections which favour some kind of mid latitude block over or to the north of Britain, and the breakdown happens at T+192, so I don't think it's worth reading too much into the ECM's extended output- the same goes for the colder, wintrier picture that the GFS shows. Winds should be vectored somewhere between N and E until T+168 bringing snow showers, that's the main thing that the models are showing. The ECMWF is overall the most accurate model in the world, but no model is accurate beyond 6 days out.

And indeed, if the south-westerlies do return by T+216 (which I find unlikely) it will nonetheless have been the longest cold spell since the 1980s.

This is such a severe wintry spell coming up for the next six days it would be a shame if it all ended as the ecm 12z suggests with a very tame looking breakdown to milder weather and once we lose the bitter spell it will probably be difficult to get it back again, the gfs has been pretty sub standard recently despite it's upgrade but hopefully it currently has a better grasp on the pattern unless it goes the same way as the ecm tomorrow, I don't think the gfs 18z will react to the ecm signal but then the 00z will be very important as that brings the potential pattern change just within the reliable timeframe.

[tinybill]

all i say looking at the models to-night its looking very juicy for about Jan 6 if I'm reading them right!!

[Thundery wintry showers]

As per previous post- ALL models are prone to wobblers at more than 6 days out. The models are firming up on the likelihood of those spectacular NE'lys that the ECMWF first picked up on coming to fruition. What happens afterwards is open to question, and until we see strong model agreement across the board it is foolish to get upbeat or downbeat over a single run. By the same token, if ECMWF at 00Z shows a NE'ly up to T+168 veering easterly through to T+240, it's not worth getting excited over that post T+168 evolution either.

[nick sussex]

http://www.wetterzentrale.de/pics/Rjma1921.gif

JMA 192-- NOTHING like the ECM & look at the juicy WEHEEHEAAA up the western part of Greenland-

So either every model is wrong tonight or its a wobbler from the ECM- didnt this happen the other day with the gfs....

S

It does seem a better example of what should have happened given the upstream pattern, that seems plausible and quite a logical way forward. But anyway i suppose it was time for some late model drama!

[SMU]

It does seem a better example of what should have happened given the upstream pattern, that seems plausible and quite a logical way forward. But anyway i suppose it was time for some late model drama!

cheers- I feel like im asking for this everyday- I didnt save the ECM ensembles short 10 link can you post it!!!

S

[LomondSnowstorm]

cheers- I feel like im asking for this everyday- I didnt save the ECM ensembles short 10 link can you post it!!!

S

Here you go, though I don't think today's are out yet. http://www.knmi.nl/exp/pluim/

LS

[nick sussex]

cheers- I feel like im asking for this everyday- I didnt save the ECM ensembles short 10 link can you post it!!!

S

Steve theres also this one which is much bigger format but goes upto 15 days.

http://www.weerplaza.nl/15daagseverwachting/default_pluim.asp?r=midden

And the normal short link

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

[phil nw.]

http://www.wetterzen...cs/Rjma1921.gif

JMA 192-- NOTHING like the ECM & look at the juicy WEHEEHEAAA up the western part of Greenland-

So either every model is wrong tonight or its a wobbler from the ECM- didnt this happen the other day with the gfs....

S

T168hrs. on both are along similar lines though Steve.

You could see how at this cruical point where the Greeny blocks gives way that with a little more energy to the North how it could go wrong,ie.the ECM T192hrs.

The JMA just about gives us the cut off mid atlantic high which keeps the jet running southat T192hrs.

Must admit when i saw the ecm earlier on metioceil it looked even worse.

Hopes for 00z now.

[Frosty.]

I would like to be a fly on the wall at the NOAA discussion this evening, they tend to go with the ecm often but maybe not the 12z...hopefully not anyway.

[sebastiaan1973]

I have already for you the temperatures for De Bilt based on tonights run of ECM

1: 0/-5

2: 0/-7

3: -3/-7

4: -3/-8

5: +1/-3

6: +1/-6

7: -4/-8

8: -3/-10

9: +1/-5

10: +3/+1

I was really amazed by it, I expected somewhat higher temperatures.

[SMU]

http://www.knmi.nl/exp/pluim/

short ensembles out & clearly the 12z is at the TOP of the clustering when things start to go titicus verticus-

Its also outside the main top & bottom clustering- ( see the top & bottom flat lines)

around 15% support, but by the same token look at the control run---- thats where its at & I imagine thats inline with the GFS-

I am somewhat pleased with that- also when the extended come out I suspect there will be a HUGE divide between control & op's( Cheers LOMOND)

S

Edited December 31, 2009 by Steve Murr

[PB22]

http://www.knmi.nl/exp/pluim/

short ensembles out & clearly the 12z is at the TOP of the clustering when things start to go titicus verticus-

Its also outside the main top & bottom clustering- ( see the top & bottom flat lines)

around 15% support, but by the same token look at the control run---- thats where its at & I imagine thats inline with the GFS-

I am somewhat pleased with that- also when the extended come out I suspect there will be a HUGE divide between control & op's( Cheers LOMOND)

S

Those are yesterday's ensembles Steve, when they have updated they will have (Startdatum: 2009123112) 01 Jan above the graphs on them.

[Mikel Nimbus]

To have such distinct blocking to our south, as the ECM is suggesting, just doesn't stack up. Look at NAO forecasts. They are set to stay very negative for the first half on January. Such large pressure differences between Iceland and the Azores are much more common in a +NAO setup.

Edited December 31, 2009 by Mikel Nimbus

[MR EXTREMES]

http://www.wetterzen...cs/Rjma1921.gif

JMA 192-- NOTHING like the ECM & look at the juicy WEHEEHEAAA up the western part of Greenland-

So either every model is wrong tonight or its a wobbler from the ECM- didnt this happen the other day with the gfs....

S

it happened with the last cold spell before christmas aswell and if i remember rightly that was the ecm aswell.

oh yeah happy new year to every single person on net weather.:drinks:

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

I wonder if it will be cold enough for the water ways to freeze up enough for the Elfstedentocht!?

[NorthNorfolkWeather]

I wonder if it will be cold enough for the water ways to freeze up enough for the Elfstedentocht!?

I would be really surprised if they didn't, but it may be another 2 weeks before they know.

On the models, I think the ECM is too progressive in the breakdown, would expect the GH (or Scandi) to hold for a little longer. Lets see if it continues in the next run.

[PB22]

ECM ensembles for Reading:

http://www.ecmwf.int/samples/d/banner/page.html

Operational was not without support, the control was milder...has ECM picked up on something new tonight?

[PB22]

Is that not last nights is the date not meant to be the 1st jan!!

Afraid not, those are the ensembles from tonights 12Z ECM run.